blackMotivated by these unique benefits, recently many network architectures have been proposed by integrating blockchain in FL. For example, an integrated FL-blockchain scheme is proposed in [1]}, where both local training and global model updating are performed at mobile devices via the blockchain in the MEC network. Another integrated FL-blockchain architecture is introduced in [2]} which allows FL clients (i.e., vehicles) to collaboratively train AI models and exchange aggregated updates through blockchain miners. FL is also integrated with blockchain for an MEC-based IoT network [3]}, aiming to coordinate IoT users to train neural networks and share training parameters with MEC servers at BSs for cooperatively solving a data relaying optimization problem. A similar integrated FL-blockchain architecture is considered in [4]} to collaborate IoT devices and MEC servers at BSs. In particular, a shared global model is learned using distributed local datasets under the control of a blockchain which also provides model verification in a decentralized manner.
